Michelle Williams & Ryan Gosling at Cannes

Blue Valentine’ costars Michelle Williams and Ryan Gosling looked very comfortable and happy together throughout the photocall and premiere for their film Tuesday at the Cannes Film Festival, which of course sparked rumors they might be an item. Ryan has had a history of romancing costars, having dated Sandra Bulllock (Murder By Numbers) and Rachel McAdams (The Notebook). Michelle who looks fabulous with her adorable side-parted platinum blond do, was last linked to Spike Jonze, her first post-Heath Ledger romance.